cohlston



E. s. HcKES. PRUCESS FOR PRODUCING HYDROFLUORIC ACID. APPLICATION FILED OCT- 8. l9l8. 1,316,569. Patented Sept; 23, 1919.

.Pr ww QN 7///////Q UNITED STATES PATENT OFFICE.

EDWIN S. TIGERS, F PITTSBURGH, PENNSYLVANIA.

PROCESS F03 PBODUCING HYDZBJOFLUOBIG `Allil).

Bpeoication o! Letters Yatent. llatented Sept. 23, 1919.

riglnal application lied latch $1, 1914, Serial In. 828,436. Divided and this application Oktober 8, 1918. Serial No. 967,889.

\ To allwlcms'tmay concern:

i the following is a full, clear, and exact del a method for the scri tion.

invention which constitutes the sub- ]ect matter of this application is a division of ipsy copending application, Serial No. 828, 6, filed March 31, 1914, and relates to production of hydroiuoric acid continuousl more rapidly, and more economically on a commercial scale than has heretofore been possible.

Broadl speaking the process consists in feeding e materialthrough an elongated stationary retort, agitating it and subjecting the same continuously to the action of heat which in gra'duallyn tem rature in the direction of the movement o the material thro h the retort and takingoi the hydrouoric acid as fast as formed. The reagents, which are uorspar and sulfuric acid, may be fed to the retort at one end either intermittent] or continuously and the residue (CaS.) may be removed fromy the op ite end in like manner. I have found that in employing a stationary retort .provided with a continuous agitator com rising paddles or scrapers, a v thorcogli) ery pllshed, an this in conjunction with the actionof the heat, which inc gradually in temperature in the direction of movement of the material, not only enables the latter to gradually stiil'en as 1t moves al the retort, .but v efectively prevents materialfrom -intoahardmassorfrom any undecomposed lluorspar to the action of heat and also kee the latter continuously scraped off the wal of the retort. Furthermore by employing a stationary retort itis a very slnple matter to maintain the wialluls thci'eof uidht' t, there roven -escape an roiluorildyagid fuidldg into the air or the furnace 1 the detrimental and obnoxious effects of which are very well understood. A better understanding of the process may be hadA by a ilic description of one form of the reagents may be accom-- of the retort. The pad-4 out practice, as illustrated in the accomi panying drawing, in which- Figure 1 is a longitudinal vertical section.`

Fig. 2 is a sectional plan view.

Fig. 3 is a cross section on line 3 3 of Fig. 1, omitting the agitator or mixer with which the ap aratus is preferably equipped.

Fig. 4 is a etail cross section, on a larger scale, of the tubular retort, showing the agitator.

Fig. 5 is a detail view showing means for cooling the shaft of the agitator or mixer.

The still illustrated consists, in neral, of a long, tubular, stationary retort 1 inclosed in a suitable housing or setting 11, by which a gaseous heating medium is passed along the retort, which medium may be the hot Eroducts of combustion from a furnace or re chamber 12. Vertical .baiiles 13, extending alternately from; opposite sides' of the setting cause the smoke and to take a more or less tortuous course, thereby giving a more eiiicient utilization of the heat. At the end opposite the fire chamber the products of combustion liow downwardly and laterally through a liuc 14 to theI stack, shown in horizontal Asection at 15, Fig. 2.

In the present instance, the retort 10, preferabl inclined downward toward cham for exam leatanantgle givin about a half-inch fa per foot o length, 1s formed of cast iron pipe-sections, the straight sections alternating with the T sections. The latter are turned up, and are provided with suitable closures, as 16, re-

alsobeusedtosupporth rslforthe shaft of the 'tator, desc hereinafter. The closure on the T'l'l at upper end of the retort, is provided. with means for sxi'iplying the isi: i producing mate continuousl or intermittently. In the drawing I have own a simple hopper 18, with a gate valve 19, by which convenient uantities 'of material can be delivered into t e retort atproper intervals. The closure 17 also has an outlet pipe 20 to carry oil' the hydroiluoric acid vapor and conduct the same to a suitable condenr, not shown. The vi which is preferabl made of lead or liii with lead, is provi ed with a valve 21 to regulate the rate of outiow.

At its lower end the retort terminates in il of apparatus y whichtheprocess is carried a cross 22, having at the top a removable 11o closure 23 and at the bottom a pipe 24 exsulti in a loss ofsliuorin and giving a tending below the surface of the water in consi erable amount of sulfuric acid in the pit 33, forming a water-seal. Any other hydroiluoric acid condensed. If the retort form of seal may be provided. Journaled is inclined, with the inlet for the iiuorspar o in the end closures 25, 26, 'is a shaft 27 exand sulfuric acid at the higher end, the 7o tending thro the retort at the axis there the axis of the retort, as the inclination of of and provi ed with helically arranged paddles or scra rs 29 may be parallel to radial arms 28 equipped at their ends with the latter, toget er with the agitation propaddles or scrapers 29 close to, but prefduced by the paddles, will cause the maerably not touching, the ywalls of the retort. tcrial to move through the retort at a fast 75 At the lower end-the shaft is connected with enough rate. suitable driving mechanism, as for example ,The hydrofluorc acid being given ofi?x an electric motor 30, by means of a worm 31 gradually as the mixture progresses, the and worm gear 32. process 1s in ei'ect continuous even when `Fluorspar and sulfuric acid in suitable the raw material is supplied intermittently. 80 proportions, are fed into the hot stationary Actual use of the invention has demonstill or retort at the upper end through the strated its superiority over any processes hopper 18. In the retort it is thoroughly known at the present time employed for the mixed by the revolving paddles 29, and somo purpose.

adually stiiiens as it moves slowly down What I claim is: so` into the hotter parts. Finally it breaks up, 1. The process for the production of hypart into owder and part into small balls droluoric acid which consists in continuor rounde lumpS- Menyvhll. the Ietlqn ousl movin iuorspar, and sulfuric acid in between the calcium f iuorid and the sulfuric a su anti y horizontal direction throu h 26 acid goes on, yieldilig` hydrouoric wld a station elongated retort, continuousliy (hydrogen iiupl'ld, 1n the form Qf heating an agitating the same in their pas- W201, und Cilllml Sulf' (C8504) aSfSOhd sage through the retort, and taking o' the residue.- The former goes 9E throu h the hydrouoric acid vapors as fast as formed. lead pipe 20; while the residue, as est 8S 2. The process for the production of hyo it reaches the cross 22, falls into theplt 33 `droluorio acid which consists in simultane as and 'islemOVd from tlm 110 tlm@ 111 any ously agitating and continuously moving olvmn W'y- If DSS'IY t0 Push the fluorspar and sulfuric acid in a substanresidiie out, the lid 23 may be removed for tiuuy horizontal direction through a stathef urpOS- tionary elongated retort, heating the same sa T e proportions of calcium 111101111 and as they are passing through the retort, tak- 100 sulfuricaoid may vary widely in practice. ing off the hydroiluoric acid vapors as fast Theoretically they Should be 111 equal Parts as formed, and discharging the residue from by weight) but as natural calcium uorid said rotort,

liuorspar) is always impure, equal parte 3. The process for the production of hy- 40 would in volve more or less waste of the suldrofluoric acid which consists in simultane- 105 furie acid, as a part of the latter would ously agit-,ating und continuously moving simply volatilize and escape. More definite luorspar and sulfuric acid through a staproportions cannot be given, since dierent tionary elongated retort, continuously heatlots of iiuorsparvary greatly in impurity ing the somo in their assage through the content, but the most economical proportions retort, und ,taking olf the hydrouorio acid 110 can easily be determined by analysis or trial vapors as fast as formed.`

or by both. 4. The process for the production of hydro- The temperature inside the retort or still uoric acid which consists in supplying the at the hottest parts shouldnot be less than raw material at one end of a stationary about 315 C. (600 F.) but may inelongated retort, continuously moving and 116 creased t0 any degree whleh will not 11111110 agitating the same along the length of the the retort or soften the agitator shaft so as retort, taking olf the hydrouoric acid vato cause it to twist, bend, or spring. To prepors as fast as formed, and discharging the vent overheating of the shaft and permit residue at the other end of the retort.

higher temperaturestobeused the shaftmay 5. The process for the production of hy- 120 be hollow, as in Fig. r5, for e urpose, if drouoric acid which consistsin supplying desired, of carrying water or ot er cooling the raw material at one end of a stationary medium suppllied to the lower end by a pipe elongated retort, continuously moving and 3i -and disc rged at the upper end by. a agitating the same alo the length of the p1 The couphngs 36 are of any suitretort while subjecting e sameto heat in- 126 ab ekind, permitting theshafttoturn. This creasing in temperature in the direction of shaft hould in most cases, revolve quite the flow of the material, taking off the hyslowly. If the rate of progress is too fast drofluoric acid vapors as fast `as formed, and the in i xture is heated too rapidly and causes discharging the residue at the other end of volatilization of the s ulfuric acid, thus rethe retort. 180

6. The process for the production of hydrolluoric acid which consists in moving fluorspar and sulfuric acid in a substantially horizontal direction through an elongated retort, continuously heating and stirrlng the same in their 1-:f-. through the retort, and takin oi the hydroiiuorlc acid vapors as fast as ormed.

7. The process for the production of hydroiiuoric acid which consists in moving uorspar and sulfuric acid continuously through an elo ted retort, heating the matenal during 1ts passage through said retort, simultaneously stirring the material to keep the same stripped from the walls of the retort and to give the heat freedom of action upon substantially all portions of the material, and taking oif the hydro- {iuoric acid vapors as fast as formed.

8. The process for the continuous production of hydroiluoric acid which consists in moving fluorspar and sulfuric acid in a substantia 1y horizontal direction throuh an elongated retort, heafti the materi during its passage through t e retort, constantly stirring the material in its passage to revnt its baking into hard masses, contihuously stripping from-'the inner walls of the retort any material adh thereto to enable a free transfer of the eat to any undeccmposed uorspar, and taking olf the'hydroliuoric acid as fast ras formed.

9. The process for ,the continuous production of hydroiluoric acid which consists in continuously'moving iuorspar and sulfurie acid in a substantiall horizontal direction through an elonga retort, suab] ecting the material in the retort to heat increasing in temperature in the direction of movement `of the material, constantly stirrin the material lin its p to prevent its inlto hard masses, continuously stripping from the inner wall of theretort any .material tendin to adhere thereto to enable a free trans er of the heat to any undecomposed iiuorspar, and taking of the hydroluoric acid vapors as fast as formed.

In testimony whereof I hereunto aiiix my si alture.

gn EDWIN s. FICKES.

Correction In Letters Patent No. 1,316,569.

Itis hereby certied that in Letters Patent No. 1,316,569, granted September 23, 1919, upon the application of Edwin S. Fickes, of Pittsburgh, Pennsylvania, an error appeare in the printed spoccaton l'equiringeorreetion sfollows: Page 2, transpose ,lines 71 ancl72 as now numbered; and that the said Let-ters Patent should be read with this coreection therein that the same may conform to the record of the ease in the Patent Olce.

signed and sealed this 2m day of'ocwber, A. b., 1919. A

M. H. coULsToN, Adng commissioner qfPm.

[sun] 

